Minasian has been particularly bad at building a bullpen the last 3+ years. 26th in WAR and 24th in WPA during that time. Some of this has to do with the utter wasteland of arms that have come from the farm the last few years and why you'd draft all pitchers. But even still, he hasn't really gotten much from that so far.
Eppler was quite good at frankensteining the crap out the pen every year. I haven't figured out what it is, but there is a bit of secret sauce to this as Cashman is pretty amazing at it. pick pretty much any 4 or 5 year span and the yanks are near the top. Eppler was dealt a similar if not worse hand with better outcomes.
Regardless, this is a pretty significant loss imo.